Re^3: Slicing the output of a command

[BrowserUk]

Why cat the whole file just to discard all but the first four lines:

my @foo = `head -4 very_large_file`;

[marioroy]

+1 BrowserUk. I'm not sure if the behavior is the same in Windows, but the 'cat command' receives a PIPE signal and exits once count lines have been read by the 'head command'.

[afoken]

Windows has no signals, so no SIGPIPE there.

Alexander

[BrowserUk]

You're correct, however, marioroy's point holds. When head has read its 4 lines it closes the pipe and effectively prevents cat (or type or copy etc.) from reading further.

(That doesn't stop it from be a Useless use of cat though.)